Learn Rust in a Month of Lunches

22 Writing your own macros

This chapter covers

• Why macros exist
• Understanding and writing basic macros
• Learning to read macros written by others
• Using macros to reduce code duplication

It’s now time to learn how to write your own macros. Writing macros can be pretty complicated, which is why they are here near the very end of the book. You very rarely need to write them, but sometimes you might want to because they are very convenient—they essentially write code for you. They have a syntax that is pretty different from normal Rust, and they take some getting used to. Well, a lot of getting used to.

Indeed, the book Programming Rust (O’Reilly, 2021) finishes its chapter on macros with a conclusion that sums up the feeling pretty well: “Perhaps, ...